Logically-speaking, it was better for organization to keep it in its own, separate SS2 Hybrid-themed package. It also reduces the filesize of EXU-Sounds for people who maybe don't want the extra Hybrid stuff.

I am not sure when I will release Maps 17 and 18 as they are still SUPER alpha-y and haven't been properly playtested in over a year now. I have been busy working on refining, polishing, and adding features to the core code and earlier levels to bring them up to the new standards. The good news is I'm mostly done with the hard work, so I just have tweaks and polishing to do and a few bugs to fix before the next update will be ready, but it could still be a few weeks unless there's a lot of demand for new stuff.

Once I finish this round of polishing, I'll resume playtesting the campaign again in earnest for the first time in forever so I can make changes to maps 15 and 16, which I also haven't had time to test in forever (if you have issues with these maps please report them!). Then once those are tweaked if necessary, more work on 17 and 18 can be done until they are release-worthy!